How to delete a record with form data

Rails
1

Hi fellow RoR’ers,

I have a Rails app, where a user can subscribe and unsubscribe from a
mailinglist. To unsubscribe, the user can fill in their email address
in a form field.

But I have no idea how to delete the record from the database, using
the typed in data from the user. I’ve tried it with the following
code, but doesn’t seem to work.

@email = Email.find(:all, :conditions => [ “mail = ?”, params[:mail]])
@email.delete(:id)

–> no error, but nothing happens

Or this way, didn’t work either,

Email.find_by_mail(params[:email][:mail]).destroy!

–> then I got the following error: undefined method `find_by_mail’ for
Email:Class

Any ideas?

2

On 2/3/07, Johan [email protected] wrote:

@email = Email.find(:all, :conditions => [ “mail = ?”, params[:mail]])
@email.delete(:id)

→ no error, but nothing happens

There’s no instance method #delete, AFAIK. What does @email contain?
Should you be using be “params[:email][:mail]” instead? A shorter way
to do it would be with Email.destroy_all, or, if you’re really sure,
Email.delete_all.

Or this way, didn’t work either,

Email.find_by_mail(params[:email][:mail]).destroy!

→ then I got the following error: undefined method `find_by_mail’ for
Email:Class

Any ideas?

I’d expect #find_by_mail to work so long as:

  • Email derives from ActiveRecord::Base, and
  • there is a column called ‘mail’ on the corresponding table.

Which leads me to two questions:

  • Does your class declaration start with “class Email <
    ActiveRecord::Base”?
  • Have you migrated your database appropriately so your ‘emails’ table
    (unless
    you’ve used set_table_name) contains a column called ‘mail’?

HTH.

3

Aha,

Seems to work now, but without the ‘!’ at the end after destroy.

Email.find_by_mail(params[:email][:mail]).destroy

Thanks for the help! (with a ‘!’)

4

On 2/3/07, Johan [email protected] wrote:

Thanks for the help! (with a ‘!’)
I’m happy it worked for you, but if it was me, I’d certainly be
digging down deeper. “Oh it just works now” doesn’t usually satisfy
me as a developer. Calling #destroy instead of #destroy! shouldn’t
make a fleck of difference as to whether or not Email responds to
#find_by_mail. Y’know?

It’s up to you. You’re welcome either way. :slight_smile: